mv compiler to compiler/
This commit is contained in:
mark
Vadim Petrochenkov
parent
db534b3ac2
commit
9e5f7d5631
1686 changed files with 941 additions and 1051 deletions
886
compiler/rustc_traits/src/chalk/lowering.rs
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886
compiler/rustc_traits/src/chalk/lowering.rs
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@ -0,0 +1,886 @@
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//! Contains the logic to lower rustc types into Chalk types
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//!
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//! In many cases there is a 1:1 relationship between a rustc type and a Chalk type.
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//! For example, a `SubstsRef` maps almost directly to a `Substitution`. In some
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//! other cases, such as `Param`s, there is no Chalk type, so we have to handle
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//! accordingly.
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//!
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//! ## `Ty` lowering
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//! Much of the `Ty` lowering is 1:1 with Chalk. (Or will be eventually). A
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//! helpful table for what types lower to what can be found in the
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//! [Chalk book](http://rust-lang.github.io/chalk/book/types/rust_types.html).
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//! The most notable difference lies with `Param`s. To convert from rustc to
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//! Chalk, we eagerly and deeply convert `Param`s to placeholders (in goals) or
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//! bound variables (for clause generation through functions in `db`).
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//!
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//! ## `Region` lowering
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//! Regions are handled in rustc and Chalk is quite differently. In rustc, there
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//! is a difference between "early bound" and "late bound" regions, where only
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//! the late bound regions have a `DebruijnIndex`. Moreover, in Chalk all
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//! regions (Lifetimes) have an associated index. In rustc, only `BrAnon`s have
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//! an index, whereas `BrNamed` don't. In order to lower regions to Chalk, we
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//! convert all regions into `BrAnon` late-bound regions.
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//!
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//! ## `Const` lowering
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//! Chalk doesn't handle consts currently, so consts are currently lowered to
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//! an empty tuple.
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//!
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//! ## Bound variable collection
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//! Another difference between rustc and Chalk lies in the handling of binders.
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//! Chalk requires that we store the bound parameter kinds, whereas rustc does
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//! not. To lower anything wrapped in a `Binder`, we first deeply find any bound
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//! variables from the current `Binder`.
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use rustc_middle::traits::{
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ChalkEnvironmentAndGoal, ChalkEnvironmentClause, ChalkRustInterner as RustInterner,
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};
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use rustc_middle::ty::fold::TypeFolder;
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use rustc_middle::ty::subst::{GenericArg, GenericArgKind, SubstsRef};
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use rustc_middle::ty::{
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self, Binder, BoundRegion, Region, RegionKind, Ty, TyCtxt, TyKind, TypeFoldable, TypeVisitor,
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};
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use rustc_span::def_id::DefId;
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use std::collections::btree_map::{BTreeMap, Entry};
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use chalk_ir::fold::shift::Shift;
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/// Essentially an `Into` with a `&RustInterner` parameter
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crate trait LowerInto<'tcx, T> {
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/// Lower a rustc construct (e.g., `ty::TraitPredicate`) to a chalk type, consuming `self`.
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fn lower_into(self, interner: &RustInterner<'tcx>) -> T;
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::Substitution<RustInterner<'tcx>>> for SubstsRef<'tcx> {
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fn lower_into(
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self,
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interner: &RustInterner<'tcx>,
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) -> chalk_ir::Substitution<RustInterner<'tcx>> {
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chalk_ir::Substitution::from(interner, self.iter().map(|s| s.lower_into(interner)))
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::AliasTy<RustInterner<'tcx>>> for ty::ProjectionTy<'tcx> {
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::AliasTy<RustInterner<'tcx>> {
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chalk_ir::AliasTy::Projection(chalk_ir::ProjectionTy {
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associated_ty_id: chalk_ir::AssocTypeId(self.item_def_id),
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substitution: self.substs.lower_into(interner),
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})
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'tcx>>>>
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for ChalkEnvironmentAndGoal<'tcx>
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{
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fn lower_into(
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self,
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interner: &RustInterner<'tcx>,
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) -> chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'tcx>>> {
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let clauses = self.environment.into_iter().filter_map(|clause| match clause {
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ChalkEnvironmentClause::Predicate(predicate) => {
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// FIXME(chalk): forall
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match predicate.bound_atom(interner.tcx).skip_binder() {
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ty::PredicateAtom::Trait(predicate, _) => {
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let predicate = ty::Binder::bind(predicate);
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let (predicate, binders, _named_regions) =
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collect_bound_vars(interner, interner.tcx, &predicate);
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Some(
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chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
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binders,
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chalk_ir::ProgramClauseImplication {
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consequence: chalk_ir::DomainGoal::FromEnv(
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chalk_ir::FromEnv::Trait(
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predicate.trait_ref.lower_into(interner),
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),
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),
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conditions: chalk_ir::Goals::new(interner),
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priority: chalk_ir::ClausePriority::High,
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},
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))
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.intern(interner),
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)
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}
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ty::PredicateAtom::RegionOutlives(predicate) => {
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let predicate = ty::Binder::bind(predicate);
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let (predicate, binders, _named_regions) =
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collect_bound_vars(interner, interner.tcx, &predicate);
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Some(
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chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
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binders,
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chalk_ir::ProgramClauseImplication {
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consequence: chalk_ir::DomainGoal::Holds(
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chalk_ir::WhereClause::LifetimeOutlives(
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chalk_ir::LifetimeOutlives {
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a: predicate.0.lower_into(interner),
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b: predicate.1.lower_into(interner),
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},
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),
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),
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conditions: chalk_ir::Goals::new(interner),
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priority: chalk_ir::ClausePriority::High,
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},
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))
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.intern(interner),
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)
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}
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// FIXME(chalk): need to add TypeOutlives
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ty::PredicateAtom::TypeOutlives(_) => None,
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ty::PredicateAtom::Projection(predicate) => {
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let predicate = ty::Binder::bind(predicate);
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let (predicate, binders, _named_regions) =
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collect_bound_vars(interner, interner.tcx, &predicate);
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Some(
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chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
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binders,
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chalk_ir::ProgramClauseImplication {
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consequence: chalk_ir::DomainGoal::Holds(
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chalk_ir::WhereClause::AliasEq(
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predicate.lower_into(interner),
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),
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),
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conditions: chalk_ir::Goals::new(interner),
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priority: chalk_ir::ClausePriority::High,
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},
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))
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.intern(interner),
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)
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}
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ty::PredicateAtom::WellFormed(..)
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| ty::PredicateAtom::ObjectSafe(..)
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| ty::PredicateAtom::ClosureKind(..)
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| ty::PredicateAtom::Subtype(..)
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| ty::PredicateAtom::ConstEvaluatable(..)
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| ty::PredicateAtom::ConstEquate(..) => {
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bug!("unexpected predicate {}", predicate)
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}
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}
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}
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ChalkEnvironmentClause::TypeFromEnv(ty) => Some(
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chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
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chalk_ir::VariableKinds::new(interner),
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chalk_ir::ProgramClauseImplication {
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consequence: chalk_ir::DomainGoal::FromEnv(chalk_ir::FromEnv::Ty(
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ty.lower_into(interner).shifted_in(interner),
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)),
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conditions: chalk_ir::Goals::new(interner),
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priority: chalk_ir::ClausePriority::High,
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},
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))
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.intern(interner),
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),
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});
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let goal: chalk_ir::GoalData<RustInterner<'tcx>> = self.goal.lower_into(&interner);
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chalk_ir::InEnvironment {
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environment: chalk_ir::Environment {
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clauses: chalk_ir::ProgramClauses::from(&interner, clauses),
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},
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goal: goal.intern(&interner),
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}
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predicate<'tcx> {
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::GoalData<RustInterner<'tcx>> {
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// FIXME(chalk): forall
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match self.bound_atom(interner.tcx).skip_binder() {
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ty::PredicateAtom::Trait(predicate, _) => {
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ty::Binder::bind(predicate).lower_into(interner)
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}
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ty::PredicateAtom::RegionOutlives(predicate) => {
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let predicate = ty::Binder::bind(predicate);
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let (predicate, binders, _named_regions) =
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collect_bound_vars(interner, interner.tcx, &predicate);
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chalk_ir::GoalData::Quantified(
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chalk_ir::QuantifierKind::ForAll,
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chalk_ir::Binders::new(
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binders,
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chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::Holds(
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chalk_ir::WhereClause::LifetimeOutlives(chalk_ir::LifetimeOutlives {
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a: predicate.0.lower_into(interner),
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b: predicate.1.lower_into(interner),
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}),
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))
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.intern(interner),
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),
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)
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}
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// FIXME(chalk): TypeOutlives
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ty::PredicateAtom::TypeOutlives(_predicate) => {
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chalk_ir::GoalData::All(chalk_ir::Goals::new(interner))
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}
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ty::PredicateAtom::Projection(predicate) => {
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ty::Binder::bind(predicate).lower_into(interner)
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}
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ty::PredicateAtom::WellFormed(arg) => match arg.unpack() {
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GenericArgKind::Type(ty) => match ty.kind {
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// FIXME(chalk): In Chalk, a placeholder is WellFormed if it
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// `FromEnv`. However, when we "lower" Params, we don't update
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// the environment.
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ty::Placeholder(..) => chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)),
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_ => {
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let (ty, binders, _named_regions) =
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collect_bound_vars(interner, interner.tcx, &ty::Binder::bind(ty));
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chalk_ir::GoalData::Quantified(
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chalk_ir::QuantifierKind::ForAll,
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chalk_ir::Binders::new(
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binders,
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chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::WellFormed(
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chalk_ir::WellFormed::Ty(ty.lower_into(interner)),
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))
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.intern(interner),
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),
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)
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}
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},
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// FIXME(chalk): handle well formed consts
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GenericArgKind::Const(..) => {
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chalk_ir::GoalData::All(chalk_ir::Goals::new(interner))
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}
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GenericArgKind::Lifetime(lt) => bug!("unexpect well formed predicate: {:?}", lt),
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},
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ty::PredicateAtom::ObjectSafe(t) => chalk_ir::GoalData::DomainGoal(
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chalk_ir::DomainGoal::ObjectSafe(chalk_ir::TraitId(t)),
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),
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// FIXME(chalk): other predicates
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//
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// We can defer this, but ultimately we'll want to express
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// some of these in terms of chalk operations.
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ty::PredicateAtom::ClosureKind(..)
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| ty::PredicateAtom::Subtype(..)
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| ty::PredicateAtom::ConstEvaluatable(..)
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| ty::PredicateAtom::ConstEquate(..) => {
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chalk_ir::GoalData::All(chalk_ir::Goals::new(interner))
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}
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}
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::TraitRef<RustInterner<'tcx>>>
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for rustc_middle::ty::TraitRef<'tcx>
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{
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::TraitRef<RustInterner<'tcx>> {
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chalk_ir::TraitRef {
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trait_id: chalk_ir::TraitId(self.def_id),
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substitution: self.substs.lower_into(interner),
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}
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>>
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for ty::PolyTraitPredicate<'tcx>
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{
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::GoalData<RustInterner<'tcx>> {
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let (ty, binders, _named_regions) = collect_bound_vars(interner, interner.tcx, &self);
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chalk_ir::GoalData::Quantified(
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chalk_ir::QuantifierKind::ForAll,
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chalk_ir::Binders::new(
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binders,
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chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::Holds(
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chalk_ir::WhereClause::Implemented(ty.trait_ref.lower_into(interner)),
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))
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.intern(interner),
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),
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)
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::AliasEq<RustInterner<'tcx>>>
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for rustc_middle::ty::ProjectionPredicate<'tcx>
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{
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::AliasEq<RustInterner<'tcx>> {
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chalk_ir::AliasEq {
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ty: self.ty.lower_into(interner),
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alias: self.projection_ty.lower_into(interner),
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}
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>>
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for ty::PolyProjectionPredicate<'tcx>
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{
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::GoalData<RustInterner<'tcx>> {
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let (ty, binders, _named_regions) = collect_bound_vars(interner, interner.tcx, &self);
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chalk_ir::GoalData::Quantified(
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chalk_ir::QuantifierKind::ForAll,
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chalk_ir::Binders::new(
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binders,
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chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::Holds(
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chalk_ir::WhereClause::AliasEq(ty.lower_into(interner)),
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))
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.intern(interner),
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),
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)
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}
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}
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impl<'tcx> LowerInto<'tcx, chalk_ir::Ty<RustInterner<'tcx>>> for Ty<'tcx> {
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fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::Ty<RustInterner<'tcx>> {
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use chalk_ir::TyData;
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use rustc_ast as ast;
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use TyKind::*;
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let empty = || chalk_ir::Substitution::empty(interner);
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let struct_ty =
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|def_id| chalk_ir::TypeName::Adt(chalk_ir::AdtId(interner.tcx.adt_def(def_id)));
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let apply = |name, substitution| {
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TyData::Apply(chalk_ir::ApplicationTy { name, substitution }).intern(interner)
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};
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let int = |i| apply(chalk_ir::TypeName::Scalar(chalk_ir::Scalar::Int(i)), empty());
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let uint = |i| apply(chalk_ir::TypeName::Scalar(chalk_ir::Scalar::Uint(i)), empty());
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let float = |f| apply(chalk_ir::TypeName::Scalar(chalk_ir::Scalar::Float(f)), empty());
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match self.kind {
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Bool => apply(chalk_ir::TypeName::Scalar(chalk_ir::Scalar::Bool), empty()),
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Char => apply(chalk_ir::TypeName::Scalar(chalk_ir::Scalar::Char), empty()),
|
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Int(ty) => match ty {
|
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ast::IntTy::Isize => int(chalk_ir::IntTy::Isize),
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ast::IntTy::I8 => int(chalk_ir::IntTy::I8),
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ast::IntTy::I16 => int(chalk_ir::IntTy::I16),
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ast::IntTy::I32 => int(chalk_ir::IntTy::I32),
|
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ast::IntTy::I64 => int(chalk_ir::IntTy::I64),
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ast::IntTy::I128 => int(chalk_ir::IntTy::I128),
|
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},
|
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Uint(ty) => match ty {
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ast::UintTy::Usize => uint(chalk_ir::UintTy::Usize),
|
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ast::UintTy::U8 => uint(chalk_ir::UintTy::U8),
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ast::UintTy::U16 => uint(chalk_ir::UintTy::U16),
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ast::UintTy::U32 => uint(chalk_ir::UintTy::U32),
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ast::UintTy::U64 => uint(chalk_ir::UintTy::U64),
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ast::UintTy::U128 => uint(chalk_ir::UintTy::U128),
|
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},
|
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Float(ty) => match ty {
|
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ast::FloatTy::F32 => float(chalk_ir::FloatTy::F32),
|
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ast::FloatTy::F64 => float(chalk_ir::FloatTy::F64),
|
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},
|
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Adt(def, substs) => apply(struct_ty(def.did), substs.lower_into(interner)),
|
||||
Foreign(_def_id) => unimplemented!(),
|
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Str => apply(chalk_ir::TypeName::Str, empty()),
|
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Array(ty, len) => {
|
||||
let value = match len.val {
|
||||
ty::ConstKind::Value(val) => {
|
||||
chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst { interned: val })
|
||||
}
|
||||
ty::ConstKind::Bound(db, bound) => {
|
||||
chalk_ir::ConstValue::BoundVar(chalk_ir::BoundVar::new(
|
||||
chalk_ir::DebruijnIndex::new(db.as_u32()),
|
||||
bound.index(),
|
||||
))
|
||||
}
|
||||
_ => unimplemented!("Const not implemented. {:?}", len.val),
|
||||
};
|
||||
apply(
|
||||
chalk_ir::TypeName::Array,
|
||||
chalk_ir::Substitution::from(
|
||||
interner,
|
||||
&[
|
||||
chalk_ir::GenericArgData::Ty(ty.lower_into(interner)).intern(interner),
|
||||
chalk_ir::GenericArgData::Const(
|
||||
chalk_ir::ConstData { ty: len.ty.lower_into(interner), value }
|
||||
.intern(interner),
|
||||
)
|
||||
.intern(interner),
|
||||
],
|
||||
),
|
||||
)
|
||||
}
|
||||
Slice(ty) => apply(
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||||
chalk_ir::TypeName::Slice,
|
||||
chalk_ir::Substitution::from1(
|
||||
interner,
|
||||
chalk_ir::GenericArgData::Ty(ty.lower_into(interner)).intern(interner),
|
||||
),
|
||||
),
|
||||
RawPtr(ptr) => {
|
||||
let name = match ptr.mutbl {
|
||||
ast::Mutability::Mut => chalk_ir::TypeName::Raw(chalk_ir::Mutability::Mut),
|
||||
ast::Mutability::Not => chalk_ir::TypeName::Raw(chalk_ir::Mutability::Not),
|
||||
};
|
||||
apply(name, chalk_ir::Substitution::from1(interner, ptr.ty.lower_into(interner)))
|
||||
}
|
||||
Ref(region, ty, mutability) => {
|
||||
let name = match mutability {
|
||||
ast::Mutability::Mut => chalk_ir::TypeName::Ref(chalk_ir::Mutability::Mut),
|
||||
ast::Mutability::Not => chalk_ir::TypeName::Ref(chalk_ir::Mutability::Not),
|
||||
};
|
||||
apply(
|
||||
name,
|
||||
chalk_ir::Substitution::from(
|
||||
interner,
|
||||
&[
|
||||
chalk_ir::GenericArgData::Lifetime(region.lower_into(interner))
|
||||
.intern(interner),
|
||||
chalk_ir::GenericArgData::Ty(ty.lower_into(interner)).intern(interner),
|
||||
],
|
||||
),
|
||||
)
|
||||
}
|
||||
FnDef(def_id, substs) => apply(
|
||||
chalk_ir::TypeName::FnDef(chalk_ir::FnDefId(def_id)),
|
||||
substs.lower_into(interner),
|
||||
),
|
||||
FnPtr(sig) => {
|
||||
let (inputs_and_outputs, binders, _named_regions) =
|
||||
collect_bound_vars(interner, interner.tcx, &sig.inputs_and_output());
|
||||
TyData::Function(chalk_ir::Fn {
|
||||
num_binders: binders.len(interner),
|
||||
substitution: chalk_ir::Substitution::from(
|
||||
interner,
|
||||
inputs_and_outputs.iter().map(|ty| {
|
||||
chalk_ir::GenericArgData::Ty(ty.lower_into(interner)).intern(interner)
|
||||
}),
|
||||
),
|
||||
})
|
||||
.intern(interner)
|
||||
}
|
||||
Dynamic(predicates, region) => TyData::Dyn(chalk_ir::DynTy {
|
||||
bounds: predicates.lower_into(interner),
|
||||
lifetime: region.lower_into(interner),
|
||||
})
|
||||
.intern(interner),
|
||||
Closure(def_id, substs) => apply(
|
||||
chalk_ir::TypeName::Closure(chalk_ir::ClosureId(def_id)),
|
||||
substs.lower_into(interner),
|
||||
),
|
||||
Generator(_def_id, _substs, _) => unimplemented!(),
|
||||
GeneratorWitness(_) => unimplemented!(),
|
||||
Never => apply(chalk_ir::TypeName::Never, empty()),
|
||||
Tuple(substs) => {
|
||||
apply(chalk_ir::TypeName::Tuple(substs.len()), substs.lower_into(interner))
|
||||
}
|
||||
Projection(proj) => TyData::Alias(proj.lower_into(interner)).intern(interner),
|
||||
Opaque(def_id, substs) => {
|
||||
TyData::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
|
||||
opaque_ty_id: chalk_ir::OpaqueTyId(def_id),
|
||||
substitution: substs.lower_into(interner),
|
||||
}))
|
||||
.intern(interner)
|
||||
}
|
||||
// This should have been done eagerly prior to this, and all Params
|
||||
// should have been substituted to placeholders
|
||||
Param(_) => panic!("Lowering Param when not expected."),
|
||||
Bound(db, bound) => TyData::BoundVar(chalk_ir::BoundVar::new(
|
||||
chalk_ir::DebruijnIndex::new(db.as_u32()),
|
||||
bound.var.index(),
|
||||
))
|
||||
.intern(interner),
|
||||
Placeholder(_placeholder) => TyData::Placeholder(chalk_ir::PlaceholderIndex {
|
||||
ui: chalk_ir::UniverseIndex { counter: _placeholder.universe.as_usize() },
|
||||
idx: _placeholder.name.as_usize(),
|
||||
})
|
||||
.intern(interner),
|
||||
Infer(_infer) => unimplemented!(),
|
||||
Error(_) => apply(chalk_ir::TypeName::Error, empty()),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> LowerInto<'tcx, chalk_ir::Lifetime<RustInterner<'tcx>>> for Region<'tcx> {
|
||||
fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::Lifetime<RustInterner<'tcx>> {
|
||||
use rustc_middle::ty::RegionKind::*;
|
||||
|
||||
match self {
|
||||
ReEarlyBound(_) => {
|
||||
panic!("Should have already been substituted.");
|
||||
}
|
||||
ReLateBound(db, br) => match br {
|
||||
ty::BoundRegion::BrAnon(var) => {
|
||||
chalk_ir::LifetimeData::BoundVar(chalk_ir::BoundVar::new(
|
||||
chalk_ir::DebruijnIndex::new(db.as_u32()),
|
||||
*var as usize,
|
||||
))
|
||||
.intern(interner)
|
||||
}
|
||||
ty::BoundRegion::BrNamed(_def_id, _name) => unimplemented!(),
|
||||
ty::BrEnv => unimplemented!(),
|
||||
},
|
||||
ReFree(_) => unimplemented!(),
|
||||
// FIXME(chalk): need to handle ReStatic
|
||||
ReStatic => unimplemented!(),
|
||||
ReVar(_) => unimplemented!(),
|
||||
RePlaceholder(placeholder_region) => {
|
||||
chalk_ir::LifetimeData::Placeholder(chalk_ir::PlaceholderIndex {
|
||||
ui: chalk_ir::UniverseIndex { counter: placeholder_region.universe.index() },
|
||||
idx: 0,
|
||||
})
|
||||
.intern(interner)
|
||||
}
|
||||
ReEmpty(_) => unimplemented!(),
|
||||
// FIXME(chalk): need to handle ReErased
|
||||
ReErased => unimplemented!(),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> LowerInto<'tcx, chalk_ir::GenericArg<RustInterner<'tcx>>> for GenericArg<'tcx> {
|
||||
fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::GenericArg<RustInterner<'tcx>> {
|
||||
match self.unpack() {
|
||||
ty::subst::GenericArgKind::Type(ty) => {
|
||||
chalk_ir::GenericArgData::Ty(ty.lower_into(interner))
|
||||
}
|
||||
ty::subst::GenericArgKind::Lifetime(lifetime) => {
|
||||
chalk_ir::GenericArgData::Lifetime(lifetime.lower_into(interner))
|
||||
}
|
||||
ty::subst::GenericArgKind::Const(_) => chalk_ir::GenericArgData::Ty(
|
||||
chalk_ir::TyData::Apply(chalk_ir::ApplicationTy {
|
||||
name: chalk_ir::TypeName::Tuple(0),
|
||||
substitution: chalk_ir::Substitution::empty(interner),
|
||||
})
|
||||
.intern(interner),
|
||||
),
|
||||
}
|
||||
.intern(interner)
|
||||
}
|
||||
}
|
||||
|
||||
// We lower into an Option here since there are some predicates which Chalk
|
||||
// doesn't have a representation for yet (as a `WhereClause`), but are so common
|
||||
// that we just are accepting the unsoundness for now. The `Option` will
|
||||
// eventually be removed.
|
||||
impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>>>
|
||||
for ty::Predicate<'tcx>
|
||||
{
|
||||
fn lower_into(
|
||||
self,
|
||||
interner: &RustInterner<'tcx>,
|
||||
) -> Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> {
|
||||
// FIXME(chalk): forall
|
||||
match self.bound_atom(interner.tcx).skip_binder() {
|
||||
ty::PredicateAtom::Trait(predicate, _) => {
|
||||
let predicate = ty::Binder::bind(predicate);
|
||||
let (predicate, binders, _named_regions) =
|
||||
collect_bound_vars(interner, interner.tcx, &predicate);
|
||||
|
||||
Some(chalk_ir::Binders::new(
|
||||
binders,
|
||||
chalk_ir::WhereClause::Implemented(predicate.trait_ref.lower_into(interner)),
|
||||
))
|
||||
}
|
||||
ty::PredicateAtom::RegionOutlives(predicate) => {
|
||||
let predicate = ty::Binder::bind(predicate);
|
||||
let (predicate, binders, _named_regions) =
|
||||
collect_bound_vars(interner, interner.tcx, &predicate);
|
||||
|
||||
Some(chalk_ir::Binders::new(
|
||||
binders,
|
||||
chalk_ir::WhereClause::LifetimeOutlives(chalk_ir::LifetimeOutlives {
|
||||
a: predicate.0.lower_into(interner),
|
||||
b: predicate.1.lower_into(interner),
|
||||
}),
|
||||
))
|
||||
}
|
||||
ty::PredicateAtom::TypeOutlives(_predicate) => None,
|
||||
ty::PredicateAtom::Projection(_predicate) => None,
|
||||
ty::PredicateAtom::WellFormed(_ty) => None,
|
||||
|
||||
ty::PredicateAtom::ObjectSafe(..)
|
||||
| ty::PredicateAtom::ClosureKind(..)
|
||||
| ty::PredicateAtom::Subtype(..)
|
||||
| ty::PredicateAtom::ConstEvaluatable(..)
|
||||
| ty::PredicateAtom::ConstEquate(..) => bug!("unexpected predicate {}", &self),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> LowerInto<'tcx, chalk_ir::Binders<chalk_ir::QuantifiedWhereClauses<RustInterner<'tcx>>>>
|
||||
for Binder<&'tcx ty::List<ty::ExistentialPredicate<'tcx>>>
|
||||
{
|
||||
fn lower_into(
|
||||
self,
|
||||
interner: &RustInterner<'tcx>,
|
||||
) -> chalk_ir::Binders<chalk_ir::QuantifiedWhereClauses<RustInterner<'tcx>>> {
|
||||
let (predicates, binders, _named_regions) =
|
||||
collect_bound_vars(interner, interner.tcx, &self);
|
||||
let where_clauses = predicates.into_iter().map(|predicate| match predicate {
|
||||
ty::ExistentialPredicate::Trait(ty::ExistentialTraitRef { def_id, substs }) => {
|
||||
chalk_ir::Binders::new(
|
||||
chalk_ir::VariableKinds::new(interner),
|
||||
chalk_ir::WhereClause::Implemented(chalk_ir::TraitRef {
|
||||
trait_id: chalk_ir::TraitId(def_id),
|
||||
substitution: substs.lower_into(interner),
|
||||
}),
|
||||
)
|
||||
}
|
||||
ty::ExistentialPredicate::Projection(_predicate) => unimplemented!(),
|
||||
ty::ExistentialPredicate::AutoTrait(def_id) => chalk_ir::Binders::new(
|
||||
chalk_ir::VariableKinds::new(interner),
|
||||
chalk_ir::WhereClause::Implemented(chalk_ir::TraitRef {
|
||||
trait_id: chalk_ir::TraitId(def_id),
|
||||
substitution: chalk_ir::Substitution::empty(interner),
|
||||
}),
|
||||
),
|
||||
});
|
||||
let value = chalk_ir::QuantifiedWhereClauses::from(interner, where_clauses);
|
||||
chalk_ir::Binders::new(binders, value)
|
||||
}
|
||||
}
|
||||
|
||||
/// To collect bound vars, we have to do two passes. In the first pass, we
|
||||
/// collect all `BoundRegion`s and `ty::Bound`s. In the second pass, we then
|
||||
/// replace `BrNamed` into `BrAnon`. The two separate passes are important,
|
||||
/// since we can only replace `BrNamed` with `BrAnon`s with indices *after* all
|
||||
/// "real" `BrAnon`s.
|
||||
///
|
||||
/// It's important to note that because of prior substitution, we may have
|
||||
/// late-bound regions, even outside of fn contexts, since this is the best way
|
||||
/// to prep types for chalk lowering.
|
||||
crate fn collect_bound_vars<'a, 'tcx, T: TypeFoldable<'tcx>>(
|
||||
interner: &RustInterner<'tcx>,
|
||||
tcx: TyCtxt<'tcx>,
|
||||
ty: &'a Binder<T>,
|
||||
) -> (T, chalk_ir::VariableKinds<RustInterner<'tcx>>, BTreeMap<DefId, u32>) {
|
||||
let mut bound_vars_collector = BoundVarsCollector::new();
|
||||
ty.as_ref().skip_binder().visit_with(&mut bound_vars_collector);
|
||||
let mut parameters = bound_vars_collector.parameters;
|
||||
let named_parameters: BTreeMap<DefId, u32> = bound_vars_collector
|
||||
.named_parameters
|
||||
.into_iter()
|
||||
.enumerate()
|
||||
.map(|(i, def_id)| (def_id, (i + parameters.len()) as u32))
|
||||
.collect();
|
||||
|
||||
let mut bound_var_substitutor = NamedBoundVarSubstitutor::new(tcx, &named_parameters);
|
||||
let new_ty = ty.as_ref().skip_binder().fold_with(&mut bound_var_substitutor);
|
||||
|
||||
for var in named_parameters.values() {
|
||||
parameters.insert(*var, chalk_ir::VariableKind::Lifetime);
|
||||
}
|
||||
|
||||
(0..parameters.len()).for_each(|i| {
|
||||
parameters
|
||||
.get(&(i as u32))
|
||||
.or_else(|| bug!("Skipped bound var index: ty={:?}, parameters={:?}", ty, parameters));
|
||||
});
|
||||
|
||||
let binders = chalk_ir::VariableKinds::from(interner, parameters.into_iter().map(|(_, v)| v));
|
||||
|
||||
(new_ty, binders, named_parameters)
|
||||
}
|
||||
|
||||
crate struct BoundVarsCollector<'tcx> {
|
||||
binder_index: ty::DebruijnIndex,
|
||||
crate parameters: BTreeMap<u32, chalk_ir::VariableKind<RustInterner<'tcx>>>,
|
||||
crate named_parameters: Vec<DefId>,
|
||||
}
|
||||
|
||||
impl<'tcx> BoundVarsCollector<'tcx> {
|
||||
crate fn new() -> Self {
|
||||
BoundVarsCollector {
|
||||
binder_index: ty::INNERMOST,
|
||||
parameters: BTreeMap::new(),
|
||||
named_parameters: vec![],
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> TypeVisitor<'tcx> for BoundVarsCollector<'tcx> {
|
||||
fn visit_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> bool {
|
||||
self.binder_index.shift_in(1);
|
||||
let result = t.super_visit_with(self);
|
||||
self.binder_index.shift_out(1);
|
||||
result
|
||||
}
|
||||
|
||||
fn visit_ty(&mut self, t: Ty<'tcx>) -> bool {
|
||||
match t.kind {
|
||||
ty::Bound(debruijn, bound_ty) if debruijn == self.binder_index => {
|
||||
match self.parameters.entry(bound_ty.var.as_u32()) {
|
||||
Entry::Vacant(entry) => {
|
||||
entry.insert(chalk_ir::VariableKind::Ty(chalk_ir::TyKind::General));
|
||||
}
|
||||
Entry::Occupied(entry) => match entry.get() {
|
||||
chalk_ir::VariableKind::Ty(_) => {}
|
||||
_ => panic!(),
|
||||
},
|
||||
}
|
||||
}
|
||||
|
||||
_ => (),
|
||||
};
|
||||
|
||||
t.super_visit_with(self)
|
||||
}
|
||||
|
||||
fn visit_region(&mut self, r: Region<'tcx>) -> bool {
|
||||
match r {
|
||||
ty::ReLateBound(index, br) if *index == self.binder_index => match br {
|
||||
ty::BoundRegion::BrNamed(def_id, _name) => {
|
||||
if self.named_parameters.iter().find(|d| *d == def_id).is_none() {
|
||||
self.named_parameters.push(*def_id);
|
||||
}
|
||||
}
|
||||
|
||||
ty::BoundRegion::BrAnon(var) => match self.parameters.entry(*var) {
|
||||
Entry::Vacant(entry) => {
|
||||
entry.insert(chalk_ir::VariableKind::Lifetime);
|
||||
}
|
||||
Entry::Occupied(entry) => match entry.get() {
|
||||
chalk_ir::VariableKind::Lifetime => {}
|
||||
_ => panic!(),
|
||||
},
|
||||
},
|
||||
|
||||
ty::BrEnv => unimplemented!(),
|
||||
},
|
||||
|
||||
ty::ReEarlyBound(_re) => {
|
||||
// FIXME(chalk): jackh726 - I think we should always have already
|
||||
// substituted away `ReEarlyBound`s for `ReLateBound`s, but need to confirm.
|
||||
unimplemented!();
|
||||
}
|
||||
|
||||
_ => (),
|
||||
};
|
||||
|
||||
r.super_visit_with(self)
|
||||
}
|
||||
}
|
||||
|
||||
/// This is used to replace `BoundRegion::BrNamed` with `BoundRegion::BrAnon`.
|
||||
/// Note: we assume that we will always have room for more bound vars. (i.e. we
|
||||
/// won't ever hit the `u32` limit in `BrAnon`s).
|
||||
struct NamedBoundVarSubstitutor<'a, 'tcx> {
|
||||
tcx: TyCtxt<'tcx>,
|
||||
binder_index: ty::DebruijnIndex,
|
||||
named_parameters: &'a BTreeMap<DefId, u32>,
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> NamedBoundVarSubstitutor<'a, 'tcx> {
|
||||
fn new(tcx: TyCtxt<'tcx>, named_parameters: &'a BTreeMap<DefId, u32>) -> Self {
|
||||
NamedBoundVarSubstitutor { tcx, binder_index: ty::INNERMOST, named_parameters }
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> TypeFolder<'tcx> for NamedBoundVarSubstitutor<'a, 'tcx> {
|
||||
fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
|
||||
self.tcx
|
||||
}
|
||||
|
||||
fn fold_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> Binder<T> {
|
||||
self.binder_index.shift_in(1);
|
||||
let result = t.super_fold_with(self);
|
||||
self.binder_index.shift_out(1);
|
||||
result
|
||||
}
|
||||
|
||||
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
|
||||
t.super_fold_with(self)
|
||||
}
|
||||
|
||||
fn fold_region(&mut self, r: Region<'tcx>) -> Region<'tcx> {
|
||||
match r {
|
||||
ty::ReLateBound(index, br) if *index == self.binder_index => match br {
|
||||
ty::BoundRegion::BrNamed(def_id, _name) => {
|
||||
match self.named_parameters.get(def_id) {
|
||||
Some(idx) => {
|
||||
return self.tcx.mk_region(RegionKind::ReLateBound(
|
||||
*index,
|
||||
BoundRegion::BrAnon(*idx),
|
||||
));
|
||||
}
|
||||
None => panic!("Missing `BrNamed`."),
|
||||
}
|
||||
}
|
||||
ty::BrEnv => unimplemented!(),
|
||||
ty::BoundRegion::BrAnon(_) => {}
|
||||
},
|
||||
_ => (),
|
||||
};
|
||||
|
||||
r.super_fold_with(self)
|
||||
}
|
||||
}
|
||||
|
||||
/// Used to substitute `Param`s with placeholders. We do this since Chalk
|
||||
/// have a notion of `Param`s.
|
||||
crate struct ParamsSubstitutor<'tcx> {
|
||||
tcx: TyCtxt<'tcx>,
|
||||
binder_index: ty::DebruijnIndex,
|
||||
list: Vec<rustc_middle::ty::ParamTy>,
|
||||
crate params: rustc_data_structures::fx::FxHashMap<usize, rustc_middle::ty::ParamTy>,
|
||||
crate named_regions: BTreeMap<DefId, u32>,
|
||||
}
|
||||
|
||||
impl<'tcx> ParamsSubstitutor<'tcx> {
|
||||
crate fn new(tcx: TyCtxt<'tcx>) -> Self {
|
||||
ParamsSubstitutor {
|
||||
tcx,
|
||||
binder_index: ty::INNERMOST,
|
||||
list: vec![],
|
||||
params: rustc_data_structures::fx::FxHashMap::default(),
|
||||
named_regions: BTreeMap::default(),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> TypeFolder<'tcx> for ParamsSubstitutor<'tcx> {
|
||||
fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
|
||||
self.tcx
|
||||
}
|
||||
|
||||
fn fold_binder<T: TypeFoldable<'tcx>>(&mut self, t: &Binder<T>) -> Binder<T> {
|
||||
self.binder_index.shift_in(1);
|
||||
let result = t.super_fold_with(self);
|
||||
self.binder_index.shift_out(1);
|
||||
result
|
||||
}
|
||||
|
||||
fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
|
||||
match t.kind {
|
||||
// FIXME(chalk): currently we convert params to placeholders starting at
|
||||
// index `0`. To support placeholders, we'll actually need to do a
|
||||
// first pass to collect placeholders. Then we can insert params after.
|
||||
ty::Placeholder(_) => unimplemented!(),
|
||||
ty::Param(param) => match self.list.iter().position(|r| r == ¶m) {
|
||||
Some(_idx) => self.tcx.mk_ty(ty::Placeholder(ty::PlaceholderType {
|
||||
universe: ty::UniverseIndex::from_usize(0),
|
||||
name: ty::BoundVar::from_usize(_idx),
|
||||
})),
|
||||
None => {
|
||||
self.list.push(param);
|
||||
let idx = self.list.len() - 1;
|
||||
self.params.insert(idx, param);
|
||||
self.tcx.mk_ty(ty::Placeholder(ty::PlaceholderType {
|
||||
universe: ty::UniverseIndex::from_usize(0),
|
||||
name: ty::BoundVar::from_usize(idx),
|
||||
}))
|
||||
}
|
||||
},
|
||||
|
||||
_ => t.super_fold_with(self),
|
||||
}
|
||||
}
|
||||
|
||||
fn fold_region(&mut self, r: Region<'tcx>) -> Region<'tcx> {
|
||||
match r {
|
||||
// FIXME(chalk) - jackh726 - this currently isn't hit in any tests.
|
||||
// This covers any region variables in a goal, right?
|
||||
ty::ReEarlyBound(_re) => match self.named_regions.get(&_re.def_id) {
|
||||
Some(idx) => self.tcx.mk_region(RegionKind::ReLateBound(
|
||||
self.binder_index,
|
||||
BoundRegion::BrAnon(*idx),
|
||||
)),
|
||||
None => {
|
||||
let idx = self.named_regions.len() as u32;
|
||||
self.named_regions.insert(_re.def_id, idx);
|
||||
self.tcx.mk_region(RegionKind::ReLateBound(
|
||||
self.binder_index,
|
||||
BoundRegion::BrAnon(idx),
|
||||
))
|
||||
}
|
||||
},
|
||||
|
||||
_ => r.super_fold_with(self),
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue